#include<iostream>

#include<cstdio>

#include<cmath>

#include<cstdlib>

#include<cstring>

#include<algorithm>

using namespace std;

int read()

{

    int x=,f=;char c=getchar();

    while (c<''||c>'') {if (c=='-') f=-;c=getchar();}

    while (c>=''&&c<='') x=(x<<)+(x<<)+(c^),c=getchar();

    return x*f;

}

#define N 75

int n,m,b[N],f[N][N][N],sum[N];

struct data

{

    int x,y,z;

    bool operator <(const data&a) const

    {

        return x<a.x;

    }

}a[N];

int main()

{

#ifndef ONLINE_JUDGE

    freopen("bzoj1564.in","r",stdin);

    freopen("bzoj1564.out","w",stdout);

    const char LL[]="%I64d\n";

#else

    const char LL[]="%lld\n";

#endif

    n=read(),m=read();

    for (int i=;i<=n;i++) a[i].x=read();

    for (int i=;i<=n;i++) b[i]=a[i].y=read();

    for (int i=;i<=n;i++) a[i].z=read();

    sort(a+,a+n+);sort(b+,b+n+);

    for (int i=;i<=n;i++) a[i].y=lower_bound(b+,b+n+,a[i].y)-b;

    for (int i=;i<=n;i++) sum[i]=sum[i-]+a[i].z;

    memset(f,,sizeof(f));

    for (int i=;i<=n;i++)

    {

        for (int k=;k<=n;k++)

        f[i][i-][k]=;

        for (int k=;k<=a[i].y;k++)

        f[i][i][k]=a[i].z;

        for (int k=a[i].y+;k<=n;k++)

        f[i][i][k]=a[i].z+m;

    }

    for (int k=;k<=n;k++) f[n+][n][k]=;

    for (int k=;k<=n;k++)

        for (int i=;i<=n-k+;i++)

        {

            int j=i+k-;

            for (int root=i;root<=j;root++)

            {

                f[i][j][a[root].y]=min(f[i][j][a[root].y],f[i][root-][a[root].y]+f[root+][j][a[root].y]+sum[j]-sum[i-]);

                for (int d=;d<=n;d++)

                f[i][j][d]=min(f[i][j][d],f[i][root-][d]+f[root+][j][d]+sum[j]-sum[i-]+m);

            }

            for (int d=n;d>=;d--) f[i][j][d]=min(f[i][j][d],f[i][j][d+]);

        }

    cout<<f[][n][];

    return ;

}